Two Microtrain Z or Nn3 freight truck frames and eight Marklin metal wheel sets are required. I have built brass side frame inserts using two methods. The simpler one involves drilling #73 holes for the axle points to poke through and into the plastic side frame cones. The contact inserts rest against the outside of the wheels and ride on the axle just inside of the points. The more complex but better method is to form cone bearing races in the brass strip and fabricate something like that used in the side of the Kato N scale Mikado trucks. I use an aluminum block with a dimple hammered into it and a steel cone punch that I ground down from an old drill bit while spinning it in my Dremel tool. The point has to be rounded a little so it will not tear through the brass stock. I first make a bearing point in one end of a strip of .01" brass. Use a divider to measure the wheel spacing on the MT truck frame. With one point of the divider inserted into the first hole, mark the location for the second hole using the other point of the divider. Use a sewing needle mounted in a pin vice to open up a good center point for the punch or drill. I did this for two side frames side by side. File or grind away most of the strip leaving only a small area around the holes and a connecting piece between them that clears the cross brace on the truck. Solder a length of fine wire (such as wire from Richmond Controls on their micro-bulbs) to each of the brass plates. Next removed the insulated wheels from the 8 Marklin wheel sets. The axle on the inside of each wheel is cut off leaving a stub axle about 3/32” (2.3mm, .09") long. Insert these into a 3/16” (5.3mm, .02”) piece of Evergreen .08” diameter styrene rod with the inside is drilled out with a #74 bit. Note: The stub axles should not be long enough to touch each other on the inside of the tubing. The bearing cones pressed into the brass strip require a little more clearance in the plastic truck frame so I drilled out enough material on the inside to accept them. Assemble the trucks with the side plates mounted outside the wheels and the needle points in the bearing cones. If you use the more simple drilled hole method, the axle points extend through the clearance holes to rest in the plastic bearing cones in the truck side frames. Wire the jumper wires from the side frames to the appropriate motor contacts. This is a Bachmann 4-4-0 tender from a locomotive that I converted to Nn3.
Wow! And thanks. The pictures you posted makes this really look doable! I think I will have to give this a try. Scince all I have is micro trains cars, I'll have to pick up a few Marklin for the metal wheels sets. What gauge of wire did you use to connect the contact strips to the motor? What I really want to do is convert the tender in my mcro-trains mogul to be powered simply because I know it will creep very nice if I can just keep the current flowing. It keeps a steady 35 scale mph for me right now and that looks nice. Going backwards it creeps rather nicely as that makes the center driver make contact. So I figure with constant current it should really be able to slow down. Again let me say thanks for clearly posting with pictures, a person can explain in words, but a picture is as they say worth a thousand.
For the tender in the photo I used some colored wire left over from a DCC decoder installation. It was a little stiff so I have since replaced it with some tiny stranded wire that came off of some 1.5 volt micro bulbs. I have also heard of people salvaging wire out of cheep Walkman head phone cables. It is very small and flexible. One way to transfer power from the tender to the motor in the locomotive is to make a draw bar out of double sided copper PC board that you can usually find at Radio Shack. Solder your wires to the top and bottom at either end and then you don't have the wires going between the engine and tender.
I think I do have some old walkman wire around, however now that you mentioned it, making a drawbar might be an even better way. It is really funny, I can't help but wonder why the z scale companies just didn't go and copy the style of the tender in kato Mikado in N scale and power the tender? Heck, bachman did and their latest releases are pretty darn nice. Thanks again for the info.
This is fantastic! I was out of town on business when this was posted, and somehow it completely passed underneath my Z Radar! I will have to do this mod myself, as I really need tender pickup on a few of my DCC equipt Z Steamers. It would also work well as a method of putting lighting in some Z cabooses!
I had to revisit this post and kick it back up for people to see. This is a great idea for getting tender pickup on a Marklin Steamer, and now that I got my Bumble Bee Mogul in, I am thinking I want to try this for electrical pickup enhancement. -Robert
Some alternatives to think about: 1) www.ngineering.com has some very tiny, extremely flexible wire specifically for this purpose. 2) buy old cheap record players at garage sales, take the tone arm wire out of them, and discard the rest. Most vinyl players go for a buck. 3) Ignore the seller on eBay who has "tone arm wire" for sale for a couple bucks and a buck more for shipping. Its as stiff as a coat hanger. 4) Don't get carried away and use too small a gauge wire - remember when the loco jumps the rails on a turnout, and shorts out, you tender will be passing the entire output of the power pack to the wires headed to the engine. 5) Don't use solid wire. my 2 cents Bill K. Houston
I got me some #32 AWG wire, and #38AWG wire too! The 38 gauge stuff will only carry 100 milliamps, but the 32 will do 600mA, so i'll use that. I spent the day scratch building a tender for my Mogul, (well about 2 hours anyways) and took some photos this afternoon. Now I need to think about making those pickups, and getting me some metal wheels. -Robert
